Viscous fluids are commonly used in many commercial applications. Examples of such fluids include thermoplastic materials, lubricants and inks such as plastisol ink. Due to their viscosity, these types of fluids present various problems associated with the pouring and handling thereof.
The dispensing of materials such as plastisol inks, for example, presents various complications. Firstly, these types of inks are normally purchased in containers that need to be emptied into a feed tank of a dispensing apparatus. Such transfer presents a number of problems due to the “sticky” nature of the material. For example, the transfer process is generally time consuming and, due to the high cost of plastisol inks, requires a manual scraping of the containers to minimize loss of material. In addition, once the ink is supplied to a pumping apparatus, the highly viscous nature of the material usually results in inconsistent spurting of the material due to cavitation of the pump.
Various dispensing systems for viscous fluids have been provided in the prior art. Examples of such systems include those taught in the following U.S. Pat. Nos.: 4,635,820; 4,790,456; 5,170,710; and, 5,275,100. However, these prior art devices do not adequately address the above issues.
It is an object of the present invention to provide a fluid dispensing apparatus that addresses some of the deficiencies of known devices.